Linux Server Hacks, Volume Two

Hack #93. Recover Lost Partitions

If you can't mount any of the partitions on a hard drive, you may simply need to recreate the partition table. Here's a handy utility for identifying possible partition entries.

Seeing messages like "/dev/FOO: device not found" is never a good thing. However, this message can be caused by a number of different problems. There isn't much you can do about a complete hardware failure, but if you're "lucky" your disk's partition table may just have been damaged and your data may just be temporarily inaccessible.

Tip

If you haven't rebooted, execute the cut lproc /partitions command to see if it still lists your device's partitions.

Unless you have a photographic memory, your disk contains only a single partition, or you were sufficiently disciplined to keep a listing of its partition table, trying to guess the sizes and locations of all of the partitions on an ailing disk is almost impossible without some help. Thankfully, Michail Brzitwa has written a program that can provide exactly the help you need. His gpart (guess partitions) program scans a specified disk drive and identifies entries that look like partition signatures. By default, gpart displays only a listing of entries that appear to be partitions, but it can also automatically create a new partition table for you by writing these entries to your disk. That's a scary thing to do, but it beats the alternative of losing all your existing data.

Tip

If you're just reading this for information and aren't ...